| 摘要 |
PROBLEM TO BE SOLVED: To provide a recorded information reading device for reading information from a recording medium in an envelope at a sufficient distance. SOLUTION: A device is provided for reading information recorded with high density by using paint. Specifically, a one- to three-dimensional record pattern is formed on a substrate by using a material having a characteristic absorption in a terahertz band, and further a recording plate is formed by recording multiplexed information in a frequency region. Information is read by irradiating the recording plate with a terahertz wave and using a spectroscopic means. The terahertz wave may be a pulsed wave. In this case, a wave transmitted through, or reflected from, a recording region is measured with a time-domain spectroscopy, terahertz wave pulses reflected from the recording regions are separated, and information recorded on the recording regions are read out. Even when the recording plate is shielded from the wave, information can be read. The information can be recorded in high confidentiality In addition, by using colors apparently the same, confidentiality is enhanced. COPYRIGHT: (C)2011,JPO&INPIT |
